Reproducing and translating



Jan. 3, 1950 w, BALTQssER 2,493,519

REPRODUCING AND TRANSLATING APPARATUS Filed Dec. 29, 1948 33 Sheets-Sheet 1 IN VEN TOR.

R. w. BALTOSSER REPRODUCING AND TRANSLATING APPARA-TUS- Jan. 3, 1950 5 Sheets-Sheet 2 Filed Dec. 29, 1948 .lllllllllllllllllllll INVENTOR. ZZ/BQZZ'OSSQZ 8 66 O FM W jiaeri 'Jan- 1950 R. w. BALTOSSER 2,493,519

REPRODUCING QND TRANSLATING APPARATUS Filed De. 29, 1948 s Sheets-Sheet 5 g INVENTOR. 1% J9 fZaerZ Zflfiaihsser 6 Jan. 3, 1950 Filed Dec. 29, 19 48 R. w. BALTOSSER 2,493,519

REPRODUC'ING AND TRANSLATING APPARATUS 5 Sheets-Sheet 4 ATTENUATOR ATTENUATOR OATTENUATO'R c ATTEN UATOR QATTENUATOR c o 0 OUTPUTTERMINAL BOARD INDICATING o 0 j METER INVENTOR.

J20 berZZZ/Ball'asewf M M M ,T W

Jan. 3, 1950 R. w. BALTOSSER REPRODUCING AND TRANSLATING APPARATUS Filed Dec. 29, 1948 5 Sheets-Sheet 5 $2 INVENTOR. floberilflfiazfiasev Patented Jan. 3, 1950 REPRODUCING AND TRANSLATING APPARATUS Robert W. Baltosser, Tulsa, Okla., assignor to Seismograph Service Corporation, Tulsa, Okla,

a corporation of Delaware Application December 29, 1948, Serial No. 67,932

11 Claims.

This invention relates to reproducing and translating apparatus, more particularly to apparatus for translating variable amplitude or variable density film records into corresponding electrical signals and the invention has for an object the provision of reproducing apparatus of this character which is of compact and rugged construction, is readily controllable and is highly flexible in its operation.

In a co-pending application Serial No. 721,559 filed January 11, 1947, now Patent No. 2,463,534, in the name of James E. Hawkins, for Method and apparatus for analyzing seismographic records, which application is assigned to the same assignee as the present invention, there is described and broadly claimed reproducing and translating apparatus for analyzing wave records, wherein a hollow rotatable drum formed of light transmitting material and means for supporting a wave record on the drum in readily releasable fashion for rotation with the drum are provided,

together with a fixed source of light outside of the drum for transmitting a beam of light through the wave record and drum onto a detachabl-y supported photoelectric cell assembly including a plurality of photoelectric cells for converting the beam of light as caused to vary by the variable area information contained on the record into variable electric signals. In the apparatus disclosed in the said Hawkins application variable speed motor means are provided for rotating the hollow transparent drum and the output circuits of the photoelectric cells contained in the photoelectric cell assembly are connected to suitable signal amplifying means.

The reproducing apparatus disclosed in the said Hawkins application, although particularly applicable to the analysis of seismographic records, is not limited thereto but may be employed generally in the analysis, reproduction and utilization of various other types of records. To this end it is desirable to provide for a high degree of flexibility, adjustability and accurate control of the apparatus, and accordingly it is a further object of this invention to provide reproducing and translating apparatus of the above indicated character which is capable of general application to various uses.

It is a further object of the invention to provide a self-contained apparatus of the above character which is of rugged construction and readily portable.

Still another object of the present invention is to provide reproducing apparatus for simultaneously translating into electric signals a plurality of record traces on a single film wherein means are provided for independent adjustment, monitoring and control of the various signal output circuits.

Another object of the invention is to provide a compactly constructed apparatus wherein the various parts thereof are readily accessible for adjustment, inspection and repair.

In carrying out the invention in one form a reproducing and translating apparatus of the type disclosed in the said Hawkins application is provided with means for individually and selectively Fig. 1 is a front view of reproducing and trans-' lating apparatus embodying the present invention, with certain of the removable panels of the enclosing cabinet open and with the photoelectric cell assembly in partially disassembled relation;

Fig. 2 is a bottom plan view of the apparatus shown in Fig. 1;

Fig. 3 .is a top plan view with the top of the cabinet open and partially broken away, illustrating the arrangement of various portions of the apparatus within the cabinet;

Fig. 4 is a view similar to Fig. 3 but with a portion of the front wall and the various components carried thereby removed from the nor-' mal position shown in Fig. 3;

Fig. 5 is a somewhat diagrammatic fragmentary top plan view, showing the fixed light source, a portion of the light path and the rotatable drum and photoelectric cell assembly embodied in the apparatus of Figs. 1 to 4;

Fig. 6 is a view similar to Fig. 5 but showing the parts in elevation and partially in section;

Fig. '7 is an end elevational view of the apparatus shown in Figs. 1 to 4 inclusive; and

Fig. 8 is a diagrammatic representation of some of the circuits and component parts'embodied in the apparatus of Figs. 1 to 7, inclusive;

Fig. 9 diagrammatically illustrates the circuit arrangement provided to control the film driving motor and the energizing circuit for the stroboscopic synchronizing lamp embodied in the apparatus.

Referring now to the drawings, the invention is shown as embodied in reproducing and translating apparatus comprising a cabinet l having fixed end walls H and I2, and a fixedrear wall Hi, to which 'is rigidly connected by a hinge M a movable top wall 15. As shown, the'front wall of the cabinet comprises an angularly disposed fixed portion I6 and a removable vertically disposed portion l1, which is normally securedj-to the end walls H and [2 by screws l8. The front wall portions I6 and I1 cooperate to form a-- control panel on which are mountedwariousfcontrol knobs and indicating means, as will be more fully described hereinafter. Thecabinet It) also includes a bottom wall I!) which'is disposed sub stantially in the plane of the upper edge'pf-the and srecord receivin chamber comprising the legs 28 and 29, and a second'compartment 30; Disposedin-tone endrof the leg'27 of the L-shaped light is .a .ifixed source of light which, as shown "best in Fig. 6 may comprise a suitable electric light bulb 3| mounted within a-cham ber 32, having a front wall '33, in which -a suitable aperture or gate 34 is provided through whichthelight may pass into the leg 21 of the light path. Mounted'on suitable supports 35, extending from the 'wall 33, is a condensing lens structure 36 which, as shown best in Fig. -5,includes a cylindrical'lens' 31 of plano-convex'crosssection.- 'Fromthe lens 31 the light passes'along the leg 2'1 of the 'L-shaped light path and impingesupon'arefiecting mirror'38 disposed at'the intersection of the legs "21 and "2.6. From the mirror"38 the light is directed to a second mirror 39 mounted in the leg 26 on the partition :20, which mirroris efiective to directthe light beam intoallens structure 40' mounted on the partition ll.v This .lensstructure'40, as indicated in =Figs. and Lfi consists of an elongated plane-convex cylindrical lens 4|, which serves to directia ,plurality of beams :of light through "a 5suitable.:-gate or aperture 42 in the partition 2i so that the light beams pass into the leg-28 of'the L-:shaped drum and record receiving chamber.

-Mounted within the leg 28 of the L-shaped chamber opposite the aperture 42 is ahollow transparent drum 43, which is preferably formed of glass :or transparent plastic material, and which, -as shown' best in Fig. 6, is provided-at'its upper and lower edges with suitable guide-shoul ders'4 4 foreenga'ging the edges of a -film Qr-record strip-45 which surrounds the transparent drum. Althoughthe drum '43 may be mounted for -reta tion in any suitable fashion, it is shown some what diagrammatically in 'Fig. 6 as 'beingsecured to:a"base member46, which is in turn-secured to atrotatinghead-fl mounted ona shaft 49 which extends through the bottom'wall l9'ofth'e 'cabinet. The lower end of the shaft 49 is supported benearth the bottom wall of "the I cabinetyas shown mortingipanelifltfrom which is suspended a lens provided for positioning the L-shaped drum and record chamber is provided in its bottom wall with a plurality of slots 52 and 53, in which are adjustably mounted a pair of rollers 54 and 55 for receiving the film or record which is in the form of an endless belt, the rollers 54 and by reason of their adjustability providing for the mounting .of \endless record strips of varying lengths on the transparent drum 43. Suitable thumb screws 54a and 55a are rollers 54 and 55 in the slots 52 and 53.

Disposed in-the four corners of the leg 28 of thedrum receiving chamber are suitable guide members :56 (Fig.4) for receiving a plurality of supportingpins :51 (Fig. 1), which carry a supassemb1y-59 comprisin a plurality of lenses 60. This panel '58 also supports a photoelectric cell assembly 'fil, which comprises a suitable light guard 62 having a plurality of gates 63 therein, behind which are mounted 'aiplurality .of photoelectric cells 64.

The lens 41 in the lens assembly 4!! ;not :only directs the beams of light throughxthe gate .or aperture- 42' into the leg .28 of the :drum and zrecord chamber, but also .gserves to focus :the ilight on the film or record :strip *45, as "indicated diagrammatically in Fig. '5. "After" passing through the film, the various beamsuof li'ght'wliich vary in intensity in accordance with the records -contained on the film 45 pass through the lenses lill and the gates fl 'to the photoelectriccel1s 64, In Fig. 21 the film or record strip 45 -shown as bearing five separate records and in Figure "'6 thephotolectric 'cell assembly is shown as including five photoelectric cells 54. It will, of coursefibe obvious that more "or less photoelectric cells-and separate records onfilm 45 may 'be employed as desired. By virtue of the arrangement thus far described, it may be seen that the .apparatus is compactly arrangedto provide a closed light 'path 'of substantially .L shape extending from'the'fixed source "of light to the wphotoelectric cells "within the drum 43 and moreover as sh'ownb'e'st in vFig. 1, the various components of the optical system may be readily inspected merely'bylifting the top wall 15 of the cabinet, and thepane'l '58 carrying the )lens assemb1y159 and "the photoelectric cell assembly =61 may be readilyremoved. The electrical connections constituting the output circuits of the photoelectric cells include a multiple circuit :plug connector comprising the separable jplug members 65 and in Fig. "25in a supportingplate 5i], and the shaft Turning now to the circuit diagram .of Fig. :8, it willibe seen that the output circuits of the photoelectriccells 64 areindividually connected to suitableamplifiers .61, the :output circuits of which extend through individually adjustable-potentiometers "6,8 to suitable-attenuators 269, the output circuits-of which are connectedto ax'multiple plug output terminal board :10, which, as shown in .Fig. .2, is preferably mounted on the rear wall [3 .of the cabinet below the bottom 'wall l9, asimilar input terminal board H also being mounted on the rear wall and beneath the bottom wall.

In order to provide for selectivemonitoringof the amplifier output circuits so as to permit adjustment .of thepotentiometers 68, thereby to tional construction and which is indicated diagrammatically by therectangle 'lz theoutputcih cult of the vacuum tube voltmeter being connected to a suitable indicating meter 13. Associated with the vacuum tube voltmeter and the indicating meter is av multi-position selective switch 14' having three sets of contacts l5, l6 and TI. The multiple position switch 14, as shown, is provided in each set with six contacts, the last. five of which are connected in circuit with the various amplifier output circuits and the vacuum tube voltmeter 12 so as to permit individual monitoring 'of each circuit. The first contact in each set, as shown in Fig. 8, is employed when it is desired to monitor the energizing circuit for the source of light 3| As indicated diagrammatically, the light source 3| is connected to a suitable source of energy represented by the terminals 18 through an adjustable rheostat 19, so that the light level may be raised or lowered as desired, and it will be observed that when the multi-position switch 14 is in the first position shown in Fig. 8, the indicating meter 13 will be connected across the filament circuit of the light source 3| so as to measure the voltage thereacross, this circuit being traceable from one terminal of the indicating terminal I3 by way of a conductor 89, the first contact of the contact set 15 and a conductor 8|, to one side of the filament and by way of a conductor 82, the first contact of the contact set 11, a bridging conductor 83, the first contact of the switch set 16 and by way of a conductor 84 to the other side of the indicating meter.

When the multiple position switch 14 is in any one of its last five positions, the vacuum tube voltmeter 12 will be connected to a selected one of the amplifier output circuits and the output circuitof the vacuum tube voltmeter will be connected across the indicating meter 13. Assuming, for example, that the switch 14 is in its second position, a circuit may be'traced from the upper one of the amplifiers 61 through its associated rheostat 68, a conductor 85, the second contact of the contact set 11, the conductor 83, the second contact of the contact set 16, and by way of a conductor 86 to the vacuum tube voltmeter 12. The output circuit of the vacuum tube voltmeter extends from one output terminal 81 thereof through a conductor 88, the second contact of the contact set 15, the conductor 80, the indicating meter 13, and by way of a conductor 89 to the other output terminal 99 of the vacuum tube voltmeter.

In addition to the above described electrical elements, components and circuits, the reproducing and translating apparatus includes a motor 9| for driving the rotatable drum 43 and, as diagrammatically shown in Fig. 9. this motor 9| is adapted to be energized from a variable frequency source which may preferably constitute a variable frequency oscillator and amplifier unit 92, which is energized from a suitable source of energy represented by the terminals 93. In accordance with the present invention, all of the electrical components and parts illustrated diagrammatically in Figs. 8 and 9 are compactly dis-- posed within the cabinet ID in readily accessible and readily adjustable relation, some of the components being mounted beneath the bottom wall l9, as shown in Fig. 2, and the remaining components being disposed in the compartments 25 and 30, as shown best in Figs. 3 and 4. As shown in Fig. 4, the motor 9| is mounted on the bottomv wall IQ of the cabinet within the compartment 25, and is provided with a suitable shaft which extends through the bottom wall and carries a drive pulley (Fig. 2) adapted to be connected by a suitable belt 96 to the drive pulley 5| of the rotatable drum 43. If desired, tension means comprising a floating pulley 91 and a spring 98 may be provided, arranged as shown in Fig. 2,

for maintaining the belt 96 taut about the pulleys 5| and 95.

In order to provide the desired compact and readily accessible arrangement, the various components and parts which make up the above described electrical circuits are divided into subassemblies and mounted on horizontally extending panels 99 and H10 carried by the removable front wall portion II. In Fig. 3 the removable front wall portion l I is shown in its normal position with the supporting panels 99 and I00 respectively extending into the compartments 25 and 39, the panel 99 being disposed above the motor 9| and each panel carrying various electrical component parts on both the upper and lower surfaces thereof. In Fig. 4 the removable front portion I1 is shown in disassembled relation and reversed so as to expose to view the under side of the panels 99 and I0!) and the various components carried thereby.

Although the various components and parts may be arranged as desired, in the particular embodiment shown the rheostat 19 for controlling the energization of the lamp 3| is preferably mounted on the front wall portion I! above the supporting panel Hi3, and is connected to a suitable control knob |9| carried by the front wall portion I1. Similarly the multiple position switch 79 is preferably mounted beneath the horizontal panel I99 (Fig. 4) and is connected to a suitable control knob I92 carried by the wall portion H, the control knob being provided with a first position indicated by the letter L to which the switch M may be adjusted when it is desired to monitor the light source 3|, and with five other positions numbered 1 to 5, inclusive, which are employed for individually monitoring the various amplifier circuits. The indicating meter 73 is preferably located as shown in Figs. 3 and 4 on the fixed portion lb of the front wall, and a plurality of control knobs 03 are provided, one of which is associated with each of the attenuators 69, the attenuators preferably being arranged to adjust the output voltages supplied to the output terminal board in a predetermined number of uniform steps from minimum to maximum voltage.

Also mounted on the portion I6 of the front wall of the cabinet is a control knob I04 which is arranged, as hereinafter explained, to control the speed of the driving motor 9| between minimum and maximum speeds. In addition, the movable portion I! of the front wall is provided with a control knob I05, which may be employed to control the synchronizing facilities described below and, as shown in Fig. 1, the removable wall portion I! is preferably provided with a viewing panel I96, which is connected by a suitable hinge I01 and which permits inspection of the film or record 45 on the transparent drum 43. Immediatel above the control knob I95 on the front wall portion l6 of the cabinet there is mounted an indicating lamp Hi8 which when energized indicates that the synchronizing facilities are in operation.

Referring now more particularly to Fig. 9 of the drawings, the oscillator and amplifier unit 92 for energizing the film driving motor 9| with variable frequency current is in part illustrated.

astcornprising i QnICSiStfiQ e-capa'citance:oscillator.-

section which includes a thermionicztubes I09. of?

The adjustable; wipers ranged .for operation inresponse to'manual m'anipulationof-the control knob IM-to efiect variationsin the output frequencyof the unit 92. In-orderto "drive the motor 9.I. ata synchronous speeddeterrnined by the frequency of a standard sixty cycle power source H4, facilities ,areprovided for locking the output. frequency of the oscillator section ofr the unit 92. instep with a voltage derived from the sixty cycle source" I I4. These. facilities comprise the previously described switch I which is ofthe four-pole single throw type and a full wave rectifier H3.

For the purpose of making a short synchronousspeed check to determine whether or not the drum 43- is being driven at the synchronous speed determined by the frequency of the source H4, a stroboscopic light-source in the form of. 1

a neon tube H5 is provided. This tube is ar-.- ranged for excitation from the source H4 through,

r 8 ation The 120:; cycle voltage developed acrosszthe' outputrterminalszof: the: rectifier H3. and impressed across. the re-i sistor l l2 isefie'ctivestoapull the output frequency of the oscillator section. I091: of the. unit 92.into.

step therewith. .A'ccordingly,ithe motor 9| rotates at; a speed i which; is locked in synchronism. with i'thei'alternating voltage of; the source: I It. If: theia'pparatus iandLparticularly the unit; 92' is. operating; properly, the lines.-43a..on the drum 43 are-:moved in. synchronism. with theflashes de-- velopdiby'the lamps H5; with the result; that: a singlelline is eifectivelysviewedby the operator.

'On the other hand, ifrtheaoscillatonand.amplifier unitidz is not-delivering 'anioutpu't: voltage which isisynchromzedxwiththei frequency of the source II .4; the lines; 43a; will; of; course drift. in. one directionxor; the other; to provide an; indication thatthe drum: is being driven. atan'. improper speed; Thusi the. described facilities: afford an.

arrangement whereby the.speed of' operation of.- the. drum. Hi may be checked from aistandard'. commercial. current source of fixed andregulatedfrequency.

the contacts ofan on-off switch H6 and a'wave.

shaping'circuit comprising a series resistor H8, and a shuntcapacitor H9. These two circuit elements perform the'function of sharpening:

the voltage impulse delivered to the tube H5 from the source I 54 when the switch I I6 is closed.

As best shown in Fig. 4 of the drawings, the neon,

tube I I5 isdisposed in the front left corner. of the compartment 23 adjacent the base of. the drum 43. This drum has inscribed'around the lower margin thereof equi-spaced synchronizing lines 311 which are spaced a distance equal to the increment of peripheral travel of the'drum during the spacing period between flashes of the lamp II5.when this lamp is excited from a sixty cycle current source I It.

From the immediately preceding explanation, it will be understcodthat in order to make a speed check on the rotational speed of the drum=43-, the

' two switches I05 and 6- are closed. In addition, the speed control knob IE4 is adjusted-to change the output frequency of the unit 92 to approximately the value required to drive the motor SI atthe synchronous speed corresponding to the sixty cycle frequency of the. currentsource IE4; With the switch H6 closed, the lamp'l I5 is periodically ionized to produce extremely shortlight flashes which illuminate the base of the drum 43. Thus the lamp H5 acts as a strobescopic light source. With the switch I05 closed, sixty cycle energy from the source; H4 is applied to the rectifier I i3- through a transformer II I; and direct current carrying a'l20cycle ripple component is impressed across the terminals of the indicating lamp I08 in parallelwith a resistor H2 included inthe cathode leg of the oscillator tube I09; The current deliveredto the lamp lll8 is'efiective to illuminate this lamp andLthus-indicate that the synchronizingfacilitiesare in oper Whil'e-a particularembodimentof theinvention hasbeen-shown, it willb'e'understood, of course, that the invention is not limited thereto since many modificationsmay be-made and it is therefore contemplated by 1 the appended claims to cover any such" modifications ast'fall within the true spirit and scope of the invention.

What is claimedand: desired to be securedby Letters' Patent is:. I 1 f l. In a reproducing apparatus" of the type including; a light. source,la record-supporting rotatable 7 transparent drum, fphotoelect'ric cell means including a plurality of; photoelectric cells supportable within said drum, ,and output circuit means comprising individual said-apparatus and including a wall forming a. control panel, monitoring. means in said cabinet including arrindicatingv element on. saidl panel, switch, means on: said. panel" for. selectively. as.- sociatingi. saidfmonitor'in'g means. with saidlindividual 1 amplifying means "and, with! said light source, a..plurality of attenuator. means. in said outputcircuit means for individually controlling theoutput signal ,level 'offsa'id amplifying means, andmeans on said control panelfor. individually adjustingsaid attenuator. means.

'2; .Inareproduciiig. apparatus. of the. type including a lightisour'ce, arecordsupporting rotatable. transparent. drum,. photoelectric cell means includinga plurality of. photoelectric cells supportable -withirrsaid drum, and output circuit. means comprising. individual electric signal amplify-ingmeansenergizablerespectively from:

said.cells,- the-combinatiomof, a cabinetenclosing said apparatus and gincludinga frontwalliforming a control panel{andhavingatremoveable portion; horizontal panel .means: extending. rearwardly -from:said.-removeable wall-portion for supporting: components ofi'said amplifyingmeans within said cabinet in; readily 'accessible relation, monitoring means .tin. saidxcabinet including: an indicating elementtonisaidi control.- panel; switchmeans on said removeable' portion-for selectively associat-- ing said monitoring means-with said individual amplifying-means; a plurality of attenuator: means in th'e output circuit's of said-individual amplifying rneans, and means on saidcontrol panel for individually adjusting said attenuator means to" ripple :component of the:

electric signal amplifying means .e'nergizable. respectively from said cells, the combination ofi'arcabinet enclosing control the respective output signal levels of said v a control panel and having a removeable portion,

horizontal panel means extending rearwardly from said removeable wall portion for supporting components of said amplifying means within said cabinet in readily accessible relation, monitoring means in said cabinet including an indicating element on said control panel, means including a control member mounted. on said control panel for varying the energization of said light source,

] switch means on said controlpanel for selectively 'associating said monitoring means with said jindividual amplifying means or with, said light source, and attenuatormeans including a plu- ';rality of control members on said panelfor adjusting the. individual output signal levels of said amplifying means.

4. In a reproducing apparatus of the type including a light source, a record-supporting rotatable transparent drum, photoelectric cell means including a plurality of photoelectric cells supportable within said drum, and output circuit means comprising individual electric signal amplifying means energizable respectively from said cells, the combination of a cabinet enclosing said apparatus, partition means in said cabinet defining a substantially L-shaped light path hav- 'ing a light transmitting aperture in the inner wall of one leg of said path, means mounting said drum in said cabinet opposite said aperture, said cabinet including a front wall forming a control panel having an inspection panel adjacent said drum, monitoring means in said cabinet including an indicating element on said panel, switch .means on said panel for selectively associating said monitoring means with said individual amplifying means, and means for supporting component parts of, said amplifying and monitor 'ing means in said cabinetoutside of said light ,path and in readily removeable relation.

; 5. In a reproducing apparatus of the type including a light source, a record-supporting rotatable transparent drum, photoelectric cell means supportable within said drum, and outputcircuit means comprising electric signal amplifying means energizable from said photoelectric cells; the combination of a cabinet having fixed back, bottom and end walls and having removeable top and front walls; partition means in said cabinet cooperating with said walls to provide a first circuit-component compartment adjacent one end of said cabinet, an L-shaped light path having one leg extending parallel to said compartment, an L-shaped drum-and-record chamber nested within said light path, and a second circuit-component compartment nested within said L-shaped chamber; said partition means providing a light transmitting aperture between one leg of said light path and the corresponding leg of said drum-and-record chamber; means in said light path for directing a beam of light from said light source at one end of said path along the legs thereof and through said aperture and said record supporting drum to said photoelectric cell means; a pair of horizontally I disposed panels carried by said front wall and respectively extending into said circuit-component compartments for removeably supporting therein components of said output circuit means; and a panel removeably supported over said drum-and-record compartment for suspending said photoelectric cell means within said drum for ready removal therefrom when said top Wall is removed.

6. In a reproducing apparatus of the type including a light source, a record-supporting rotatable transparent drum, photoelectric cell means supportable within said drum, and output circuit means comprising electric signal amplifying means energizable from said photoelectric cells; the combination of a cabinet having fixed back, bottom and end walls and having removeable top and front walls; partition means in said cabinet cooperating with said Walls to provide a first circuit-component compartment adjacent one end of said cabinet, an L-shaped light path having one leg extending parallel to said compartment, an L-shaped drum-and-record chamber nested within said light path, and a second circuit-component compartment nested within said L-shaped chamber; said partition means providing a light transmitting aperture between one leg of said light path and the corresponding leg of said drum-and-record chamber; means in said light path for directing a beam of light from said light source at one end of said path along the legs thereof and through said aperture andsaid record supporting drum to said photoelectric cell means; monitoring means in said cabinet including an indicating element, switch means for selectively associating said monitoring means with the amplifying means of said photoelectric cells, and a pair of horizontally disposed panels carried by said front wall and respectively extending into said circuit-component compartments for removeably supporting therein components of said amplifying and monitoring means.

'7. In a reproducing apparatus of the type including a light source, a record-supporting rotatable transparent drum, photoelectric cell means supportable within said drum, and output circuit means comprising electric signal amplifying means energizable from said photoelectric cells; the combination of a cabinet; partition means in said cabinet cooperating with the outer walls thereof to provide a first compartment adjacent one end of said cabinet, an L-shaped light path having one leg extending parallel to said compartment, and L-shaped drum-and-record chamber in nested relation to said light path, and a second compartment in nested relation to said L-shaped chamber; said partition means providing a light transmitting aperture between parallel legs of said light path and chamber; means rotatably mounting said drum in one leg of said chamber opposite said aperture; means in said light path for directing a beam of light from said light source at one end of said path along the legs thereof and through said aperture and said record supporting drum to said photoelectric cell means; the front wall of said cabinet including a removeable portion; and means supported on' said moveable portion extending into said first and second compartments for removeably supporting therein components of said output circuit means.

8. In a reproducing apparatus of the type including a light source, a record-supporting rotatable transparent drum, photoelectric cell means supportable within said drum, and output circuit means comprising electric signal amplifying 1 means leiiefg izaljl trom 351d 7 htito'lectric hells;

tlfirbf to "provide anrsticompartment adjacent 7 one end or "said: cabinet'an L-shaped lightipath having "o'ne leg eiite'ndinglparalllto said com- :partment, an L-sl'iapefi drnm-and-reecrd'chamher 'in nested relatidl'l to '"Said light path, 7 ana a 7 second compartment in nested ..relation Lto said Tin 'L-fsliaped paths endless records" of various lengths supported on said drum; motor means in said first com artment includin a drive shaft extending "through said'botto'ni wall; means dl'spds d brieathsaid bfil'itdm Wall iblflCOilflCtlIlg said'sha'fts'in driving relation; 'meansih said light 135th 'fol diredtiffg a beam of light from said i s'o'urc'e at-o'ne end of sai'd path alohg thefllegs Tthe're'of a'r-id throughsaid aperture and said recare supporting drum 1130 said photoelectric -.cell

ineans; the front wan 6f said-cabinet including a 'r'einoveablemortion, and means supported lo'n said portion extending'into saidfirst andlsecdn'd eompa'r'tmerits for rmoveably supporting above sai'd-motor in said-first compartment and --in said "suspended "relation in said "Second. compartment components of. said output circuit means. 9. Apparatus for" translating into electrical sig- 1m energitthe information contained oncpartiall'y f transparent records comprisinga' housing, partif'tiohfmeans said housing defining a-subs'tantiall'y L -shaped light path having a slight tran inittihg' aperturein "the inner wall of on'eileg, (if Said path, "aicdfd-siilibditifig f'o'rmed Iof ligl'it tr'a'n s'rn ittilig material rotatably imoufited opposite said light transm ttin aperture exterior to Slaid Iigl'itLpathbut v'lithin'the confines 'Ofsaid 3 L, a-fiked light source" mounted adjacentlthe 1 end of'theo'ther leg of 'Saidlight path, means in said light path for directing a beam oflight from said sourcealong said l'egs of sal d path and tlliough said aperture to said record-supporting drum,

' means"forrdtating said and mean's inclu'ding a iphotoelec'tric cell remov'eably mounted withinisaid drum for converting said beam of light as caused to vary hya record on said drum into varying electrical energy. a 1

"10, .Apparatus for: translating into electrical signal energyfthei information contained on par- -tially "transparent records, comprising a-hou'sing, partition m'ean'sin said housing defining a Subtransmitting aperture in thefinner wall of one l eg of said path, .a record-supporting drum 'formed of light-transmitting material rotatably -mounted opposite saidzli-ght transmitting'aperture exterior to said light path but within the confines of said L, afixedlight source mounted adjacent the end of the otherleg of saidilight path, means in said-light path for directinga beam of light from said source along said legs of said path and through said aperture to said record-supporting drum, means for rotating said drum about a vertical axis,.a panel removeably supported above saiddrum and a photoelectric tially'transpa'rent records, comprising a housing,

partition meansiin said/housing defining a-substa'ntially Le'shapedlightpath having a light transmitting aperture in'the inner wall of one leg of said path, a record-supporting drum formed of light-transmitting material rotatably mounted opposite said light transmitting aper- "turje exterior to said'lightpath'but within the adjacent the endof the other leg of saidlight path, means in said "light path ."for directing a confines of said L, a fixe'd'light source mounted tioned partition means 'to form an L-shaped chamber nested within said L-shaped light path, arecord supporting drumfo'rm'ed of light transmitting material mounted in one .leg of said -"chaznberopposite said apertureforirotation'about avertical axis, 'roller'means adjustably mounted inthe'other legof saidL-sh'aped 'chamber'and cooperating with said"drum'to 'supportithere'on 'e'ndless=records of'variablelengthga fixed light source mounted adjacenttheend er the other leg of said L-sha'ped light path,"means' in said .light path for directing 'a b'eamriof light from said sourcealong saidlegs'ofsaid path and'through "said aperture tosai'dme'co'rd supporting drum, a

panel remove'ably supported :above said one leg of said: chamber, and a'photoeie'ctric 'cell assemibly carried'by' said'panel and including aphotoelectric cell suspended Within said drum "in the path "ofsaid light beam.

ROBERT W. BALTossER.

Noreferences cited. 

